"Unless we can make reasonable distinctions between what is natural and what is not, and why
that difference is important, we are liable to be at the mercy of the engineers who want to remake
all of nature, including our own. (From David Orr, from Ecological Literacy, p. 94.)"

Possible definitions of "natural" and whether or not humans or human behavior is "natural"

Sense a: Anything that happens and doesn't violate the laws of nature is natural. Contrast:
Natural vs. Supernatural. On this definition, whatever humans do is natural and
equally so.

On this definition, much
human activity counts as unnatural, though not all: Natural childbirth (as opposed
to a caesarean section) or acting on instinct is to let the spontaneous processes of
nature unfold within us and is thus not humanized.

On this view, while the products of human technology and
civilization are not natural, humans are
natural beings when born, though the process of rearing and civilizing human infants humanizes them.

Sense c: Acting in accordance with the behavior that contributed to human evolution. If the human species has
evolved to be social beings, then living a hermit lifestyle would be unnatural in
this sense. Or if humans have evolved as a heterosexual species, then engaging in
no sexual behavior or homosexual behavior would count as unnatural.

Sense e: Fitting in harmoniously with nature is natural human activity. Contrast: Living in
harmony with nature vs. disrupting nature. (Note: This sense of 'natural'
builds in a value component: Natural here entails good. The assumption here is that any natural behavior is good/moral.)

One: There is only one meaning of "the natural;" only one right way to think about what 'natural' means for all purposes and contexts.

For why this is a mistake, see the seven senses of natural distinguished above

Two: Things are either natural (sense b) or not--there are no degrees of naturalness.

A parking log, a garden, a Forest Service managed tree farm, the Smokies, the
Brooks Range--are a series of entities with increasing degrees of naturalness (in
the sense of unmanipulated by humans).

Three: Everything humans do is natural (and equally so).

On this view, toxic waste dumps are as natural as compost heaps, h-bombs & gas chambers as natural as log cabins, and cesarean sections as natural
as natural child birth.

This only makes sense if using natural in sense a

Insisting that we only use the term 'natural' in the first sense (a), results in the loss
of a useful distinction in human affairs between the more and less natural.

Four: Nothing humans do or touch is natural.

Hunter-gatherers and Native Americans are just as unnatural as are executives in
N.Y. City.

The mere human touch (or presence) makes something unnatural (e.g., a forest is
not natural because some human once camped there).

Five: Everything animals do is natural.

We do speak of the unnatural (c) behavior of animals: if a grizzly bear were to eat
its cub, for example.

Six: The natural is necessarily the good and the natural is always better than the artificial.

Consider disease, sickness, cancer cells (in one sense these are natural
phenomenon, in another sense not) and letting them flourish, versus killing them off with medicine.

Is it better to
cut fir boughs rather than use high tech sleeping pads?

Seven: Something's being unnatural is always a strike against it.

We sometimes value things because they are artificial or artifactual. We might
admire something because of the human creativity that was involved in producing
it. (We might value our child's sand sculpture more than we would an identical
sculpture produced by wind and waves.

Is this a plausible view on the natural? Being natural (b) is always (usually?) a
good feature, a value contributing feature; the natural (wild) is a prima facie value. (This does not
mean it is good all things considered, after subtracting value decreasing properties that the
natural thing might also have.)

Jay Anderson, "A Conceptual Framework for Evaluating and Quantifying Naturalness,"
Conservation Biology 5, 3, Sept 1991. Three indices of naturalness: (1) degree to which
the system would change if humans were removed; 2, the amount of cultural energy
required to maintain the functioning of the system as it currently exists, 3, the
complement of native species currently in an area compared with the species that existed
prior to settlement (also consider exotics introduced). Last two are quantifiable.